# Improvement of photovoltaic efficiency by Fano coherence

## TL;DR

This paper demonstrates that Fano resonance in a three-level atomic system can significantly enhance absorption and suppress emission through ground state coherence, potentially breaking detailed balance.

## Contribution

It introduces a novel mechanism where Fano interference induces ground state coherence, leading to improved photovoltaic efficiency.

## Key findings

- Fano resonance causes absorption enhancement.
- Emission suppression is achieved via ground state coherence.
- The effect depends on a coupling parameter from Fano interference.

## Abstract

We show that Fano resonance in the decay channels of a three-level system can lead to considerably absorption enhancement and emission suppression. We found that a coherence built up in the ground doublet states, with strength depending on a coupling parameter that arises from the Fano interference, can in principle lead to breaking of the detail balance between the absorption and emission processes in atomic systems.